Rotating hub assembly for a mining cutter bit

ABSTRACT

A mounting assembly for a mining tool adapted to fit in a bit block consisting of a hub assembly having an axial opening therethrough of a size to journal a mining cutter bit. The bit block has a larger opening adapted to accept the hub assembly and permit rotation of the hub assembly in the bit block. The hub assembly extends over the bit block so that a seal can be mounted between the bit block and the hub assembly. A peripheral groove is formed in the hub assembly so that a screw can lock the hub assembly into the bit block.

Radd et al.

Apr. 2, 1974 ROTATING HUB ASSEMBLY FOR A MINING CUTTER BIT Inventors:Frederick J. Radd; Donald H.

Oertle; Louis I-I. Wolfe, all of Ponca City, Okla.

Continental Oil Company, Ponca City, Okla.

Filed: Oct. 25, 1972 Appl. No.: 300,539

Assignee:

US. Cl 299/86, 175/334, 175/336,

175/338, 175/354, 175/371 Int. Cl. E21c 35/18 Field of Search 299/86;175/338, 354, 371,

3,519,309 7/1970 Engle et al 299/86 Primary ExaminerErnest R. PurserAttorney, Agent, or Firm-William J. Miller [57] ABSTRACT A mountingassembly for a mining tool adapted to fit in a bit block consisting of ahub assembly having an axial opening therethrough of a size to journal amining cutter bit. The bit block has a larger opening adapted to acceptthe hub assembly and permit rotation of the hub assembly in the bitblock. The hub assembly extends over the bit block so that a seal can bemounted between the bit block and the hub assembly. A peripheralgrooveis formed in the hub assembly'so that a screw can lock the hub assemblyinto the bit [56] References Cited block.

UNITED STATES PATENTS 3,498,677 3/1970 Morrow 299/86 5 Claims, 2 DrawingFigures so 52 +1; 1 2 o 1 Q 2| l 2 Q 52 x \g ATENTEUAPR 2 1974 FIG. 2

ROTATING HUB ASSEMBLY FOR A MINING CUTTER BIT PRIOR ART The closestpatent relating to the hub assembly is the patent to T. J. Kniff, U.S.Pat. No. 3,499,685. This patent discloses a bit block having a sleevemounted into the bit block and an axial opening in the sleeve adapted tohold and retain a cutter bit. The sleeve and the cutter bit are free torotate. The principal purpose of the Kniff patent is to permitreplacement of the shoulder support for the bit block. A secondarypurpose is to permit rtation of the sleeve assembly as well as thecutter bit. There is no provision, however, in the aforementioned devicefor preventing the entrance of coal dust and other materials between thebearing surfaces causing binding of the bit and loss of rotation. Sincebits are continuously washed with water, it is fairly easy to form afine water-coal slurry which will enter most exposed bearing surfaces.

Various other means have been tried to insure bit rotation. Ridges orflutes have been made on the sides of the conical bits; and projectionsof various types have been welded or attached to the base of the cone.These measures increase the bit life; however, the bit life could beincreased further if the rotation of the bit was insured.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a cross-sectional view of thehub assembly with the cutter bit in full view; and

FIG. 2 is a top view of FIG. 1 having a partial section through lines 22of FIG. 1.

Referring to both FIGS. 1 and 2, a bit block is attached to a continuousmining machine belt 11 by means of a weld or other suitable attachingmeans 12. The bit block 10 has an axial opening 13 for receiving arotatably journaling hub assembly generally referred to as 14. Hubassembly 14 essentially comprises a cylinder portion 15, a secondcylinder portion 16 having a larger diameter than portion 15, adownwardly extending circumferential lip 17, and an axial opening 18adapted to receive cutter bit 19. A plurality of impact arms 20 isattached normal to the surface of cylindrical portion 16. Axial opening18 has a circumferential groove 21 adapted to receive a locking ring 22having a plurality of dimples 23 which snap into circumferential groove21 and retain the cutter bit in axial opening 18. The cutter bit is ofthe usual type having a shank 30, a removal groove 31, a conical tip 32,and a hardened tungsten carbide insert tip 33. Such bits are readilyavailable on the market and, as such, will not be further discussed.Cylindrical portion has a circumferential groove 40 which mates with athreaded opening 41 having a bolt 42 therein. The tip 43 of bolt 42 fitsinto groove 40 and retains hub assembly 14 in axial opening 13. The sealassembly comprises a projection 50 on the bit block 10 which has arecess 51. Seal 52 fits into recess 51 and extends to the inside of thecircumferential lip 17. Since the seal is fairly well restrained frommovement, no means need be provided for anchoring the seal in recess 51.The space between bit block and cylindrical portion 15 may be lubricatedby any suitable lubricant, such as grease, oil, graphite, or the like.In some instances it may be preferable to leave any form of lubricantout of the space, since, in spite of the seal, some dust may get intothe lubricant, causing the hub assembly to bind to bit block 10 when thedust mixes with the lubricant. Operation Unlike the prior art, dust,dirt and water are prevented from entering the bearing surface betweenbit block 10 and cylindrical portion 15 by virtue of the seal 52. Anydirt or dust entering the passageway will be blocked effectively by theseal. The seal also provides for free rotation of the hub assembly. Thecutter bit 19 is also free to rotate. If the hub assembly should bind,bolt 42 can be removed and the hub assembly lifted out and cleaned. Theseal can also easily be replaced using the same procedure.

A second advantage is that, should the area around the shoulder of thecutter bit become damaged due to impacting of product, such as coal, thehub assembly can be removed; and a new one can be substituted withoutnecessitating breaking the weld 12 and substituting an entire new bitblock. The impacting arm 20 being formed on the cylindrical portion 16provides a method of insuring rotation of the hub assembly. Since theimpact arm 20 is mounted to the hub assembly, there is no need toprovide additional impact arms on the cutter bit 19, thus reducing thecost of the cutter bit. Seal 52 may be made of any suitable sealmaterial, such as rubber or one or more of the manufactured plastics.

A sealed hub assembly has been disclosed which will function in spite ofthe environmental contaminants in the region of the cutter bit. The sealassembly, furthermore, is easy to maintain.

It is obvious that modifications and changes can be made in the methodof mounting the seal or seal materials and still be within the scope ofthe specification and appended claims.

What we claim is:

l. A mounting for a mining tool comprising:

a. a bit block;

b. a hub assembly having an axial opening therethrough of a size tojournal a mining cutter bit;

c. means for rotatably journaling said hub assembly in said bit block;and d. seal means between said hub assembly and said bit block, wherebysaid hub assembly is free to rotate in said bit block, said seal meanspreventing the intrusion of dust particles on said bearing surface.

2. A mounting assembly as described in claim I wherein said hub assemblyhas a plurality of impact extensions formed normal to the surface ofsaid hub as sembly.

3. A mounting assembly as described in claim 1 wherein said hub assemblycontains a peripheral groove and wherein said bit block includes a screwmeans aligned with said peripheral groove for retaining said hubassembly in said bit block, yet permitting said hub assembly to rotate.

4. A hub assembly for a cutter bit comprising a bit block having anaxial opening therein; a hub assembly having a cylindrical portiondimensioned to fit the axial opening in said bit block, said cylindricalportion having a length sufficient to extend from said axial opening,said portion extending from said axial opening having a circumferentiallip, a circumferential seal; means for mounting said circumferentialseal between said bit block and said circumferential lip; a peripheralgroove in said cylindrical portion dimensioned to fit said axial openingin said bit block; retainer means mounted in 5. An assembly as describedin claim 4 having a plusaid bit block and engaging said circumferentialrality of impact arms mounted normal to the surface of groove; and anaxial opening in said hub assembly of a said hub assembly.

size to receive said cutter bit.

1. A mounting for a mining tool comprising: a. a bit block; b. a hubassembly having an axial opening therethrough of a size to journal amining cutter bit; c. means for rotatably journaling said hub assemblyin said bit block; and d. seal means between said hub assembly and saidbit block, whereby said hub assembly is free to rotate in said bitblock, said seal means preventing the intrusion of dust particles onsaid bearing surface.
 2. A mounting assembly as described in claim 1wherein said hub assembly has a plurality of impact extensions formednormal to the surface of said hub assembly.
 3. A mounting assembly asdescribed in claim 1 wherein said hub assembly contains a peripheralgroove and wherein said bit block includes a screw means aligned withsaid peripheral groove for retaining said hub assembly in said bitblock, yet permitting said hub assembly to rotate.
 4. A hub assembly fora cutter bit comprising a bit block having an axial opening therein; ahub assembly having a cylindrical portion dimensioned to fit the axialopening in said bit block, said cylindrical portion having a lengthsufficient to extend from said axial opening, said portion extendingfrom said axial opening having a circumferential lip, a circumferentialseal; means for mounting said circumferential seal between said bitblock and said circumferential lip; a peripheral groove in saidcylindrical portion dimensioned to fit said axial opening in said bitblock; retainer means mounted in said bit block and engaging saidcircumferential groove; and an axial opening in said hub assembly of asize to receive said cutter bit.
 5. An assembly as described in claim 4having a plurality of impact arms mounted normal to the surface of saidhub assembly.